kernel/linux.git/arch/s390/include/asm/processor.h, branch linux-5.9.y

s390: remove critical section cleanup from entry.S

2020-05-28T10:21:54+00:00

The current code is rather complex and caused a lot of subtle and hard to debug bugs in the past. Simplify the code by calling the system_call handler with interrupts disabled, save machine state, and re-enable them later. This requires significant changes to the machine check handling code as well. When the machine check interrupt arrived while being in kernel mode the new code will signal pending machine checks with a SIGP external call. When userspace was interrupted, the handler will switch to the kernel stack and directly execute s390_handle_mcck(). Signed-off-by: Sven Schnelle Signed-off-by: Vasily Gorbik

Merge tag 's390-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2020-04-04T16:45:50+00:00

Pull s390 updates from Vasily Gorbik: - Update maintainers. Niklas Schnelle takes over zpci and Vineeth Vijayan common io code. - Extend cpuinfo to include topology information. - Add new extended counters for IBM z15 and sampling buffer allocation rework in perf code. - Add control over zeroing out memory during system restart. - CCA protected key block version 2 support and other fixes/improvements in crypto code. - Convert to new fallthrough; annotations. - Replace zero-length arrays with flexible-arrays. - QDIO debugfs and other small improvements. - Drop 2-level paging support optimization for compat tasks. Varios mm cleanups. - Remove broken and unused hibernate / power management support. - Remove fake numa support which does not bring any benefits. - Exclude offline CPUs from CPU topology masks to be more consistent with other architectures. - Prevent last branching instruction address leaking to userspace. - Other small various fixes and improvements all over the code. * tag 's390-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (57 commits) s390/mm: cleanup init_new_context() callback s390/mm: cleanup virtual memory constants usage s390/mm: remove page table downgrade support s390/qdio: set qdio_irq->cdev at allocation time s390/qdio: remove unused function declarations s390/ccwgroup: remove pm support s390/ap: remove power management code from ap bus and drivers s390/zcrypt: use kvmalloc instead of kmalloc for 256k alloc s390/mm: cleanup arch_get_unmapped_area() and friends s390/ism: remove pm support s390/cio: use fallthrough; s390/vfio: use fallthrough; s390/zcrypt: use fallthrough; s390: use fallthrough; s390/cpum_sf: Fix wrong page count in error message s390/diag: fix display of diagnose call statistics s390/ap: Remove ap device suspend and resume callbacks s390/pci: Improve handling of unset UID s390/pci: Fix zpci_alloc_domain() over allocation s390/qdio: pass ISC as parameter to chsc_sadc() ...

s390/mm: cleanup virtual memory constants usage

2020-03-28T11:46:12+00:00

Remove duplicate definitions and consolidate usage of virutal and address translation constants. Signed-off-by: Alexander Gordeev Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/mm: remove page table downgrade support

2020-03-28T11:46:12+00:00

This update consolidates page table handling code. Because there are hardly any 31-bit binaries left we do not need to optimize for that. No extra efforts are needed to ensure that a compat task does not map anything above 2GB. The TASK_SIZE limit for 31-bit tasks is 2GB already and the generic code does check that a resulting map address would not surpass that limit. Signed-off-by: Alexander Gordeev Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: prevent leaking kernel address in BEAR

2020-03-10T14:16:25+00:00

When userspace executes a syscall or gets interrupted, BEAR contains a kernel address when returning to userspace. This make it pretty easy to figure out where the kernel is mapped even with KASLR enabled. To fix this, add lpswe to lowcore and always execute it there, so userspace sees only the lowcore address of lpswe. For this we have to extend both critical_cleanup and the SWITCH_ASYNC macro to also check for lpswe addresses in lowcore. Fixes: b2d24b97b2a9 ("s390/kernel: add support for kernel address space layout randomization (KASLR)") Cc: # v5.2+ Reviewed-by: Gerald Schaefer Signed-off-by: Sven Schnelle Signed-off-by: Vasily Gorbik

s390: remove obsolete ieee_emulation_warnings

2020-02-19T12:51:46+00:00

s390 math emulation was removed with commit 5a79859ae0f3 ("s390: remove 31 bit support"), rendering ieee_emulation_warnings useless. The code still built because it was protected by CONFIG_MATHEMU, which was no longer selectable. This patch removes the sysctl_ieee_emulation_warnings declaration and the sysctl entry declaration. Link: https://lkml.kernel.org/r/20200214172628.3598516-1-steve@sk2.org Reviewed-by: Vasily Gorbik Signed-off-by: Stephen Kitt Signed-off-by: Vasily Gorbik

s390: always inline disabled_wait

2019-11-30T09:52:44+00:00

disabled_wait uses _THIS_IP_ and assumes that compiler would inline it. Make sure this assumption is always correct by utilizing __always_inline. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: always inline current_stack_pointer()

2019-10-31T16:20:54+00:00

This function must be inlined since any caller expects the current stack pointer; which wouldn't be true if the function isn't inlined. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/base: remove unused s390_base_mcck_handler

2019-09-03T11:53:56+00:00

s390_base_mcck_handler was used during system reset if diag308 set was not available. But after commit d485235b0054 ("s390: assume diag308 set always works") is a dead code and could be removed. Acked-by: Heiko Carstens Signed-off-by: Vasily Gorbik

arch: replace _BITUL() in kernel-space headers with BIT()

2019-07-17T02:23:22+00:00

Now that BIT() can be used from assembly code, we can safely replace _BITUL() with equivalent BIT(). UAPI headers are still required to use _BITUL(), but there is no more reason to use it in kernel headers. BIT() is shorter. Link: http://lkml.kernel.org/r/20190609153941.17249-2-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Vineet Gupta Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds